“路旁”常见的英文表达是 “by the roadside” 或 “at the side of the road”，此外也可用 “roadside”（作名词或形容词） 来简洁表达相关含义。具体使用示例如下：
By the roadside：There were many wildflowers growing by the roadside.（路旁生长着许多野花。）
At the side of the road：We parked our car at the side of the road.（我们把车停在了路旁。）
Roadside（名词/形容词）：The roadside was lined with trees.（路旁种满了树。/ 路旁树木成行。）
根据具体语境和表达习惯，可以选择最合适的表达方式。